Esterase activity of hemoglobins: a conformational probe for difference between HbA and HbS.
(1) We have observed esterase of Hb A and Hb S. The reaction is consistent with general imidazole catalysis. (2) The rate f p-NPA hydrolysis by Hb A and Hb S is significantly different, probably due to subtle conformational alterations involving beta His 2 and/or its micro-environment in the mutant. (3) During this reaction, irreversible modification of Hb occurs, involving lysines (predominantly Lys beta 82).
D000596:Amino Acids / Q000494:pharmacology; D002256:Carbonic Anhydrases / Q000097:blood; D004163:Diphosphoglyceric Acids / Q000494:pharmacology; D004950:Esterases / Q000097:blood*; D006441:Hemoglobin A / Q000378:metabolism*; D006451:Hemoglobin, Sickle / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D011487:Protein Conformation
D000596:Amino Acids; D004163:Diphosphoglyceric Acids; D006451:Hemoglobin, Sickle; D006441:Hemoglobin A; D004950:Esterases; D002256:Carbonic Anhydrases